{"id":729,"date":"2016-08-05T10:19:29","date_gmt":"2016-08-05T10:19:29","guid":{"rendered":"https:\/\/blog.ngocha.biz\/?p=729"},"modified":"2016-08-05T10:19:29","modified_gmt":"2016-08-05T10:19:29","slug":"how-to-setup-a-zookeeper-cluster","status":"publish","type":"post","link":"https:\/\/blog.ngocha.biz\/?p=729","title":{"rendered":"How To Setup a Zookeeper Cluster – Beginners Guide"},"content":{"rendered":"

Zookeeper is a distributed coordination tool which can be used for various distributed workloads. In this article, we have explained the necessary steps to install and configure zookeeper cluster with a definite quorum.<\/p>\n

Setup a Zookeeper Cluster<\/h2>\n

Prerequisites<\/h4>\n
    \n
  1. Three VM’s. (Forms a quorum). For high availability cluster, you can go with any odd number above 3. For example, if you set up 5 servers, the cluster can handle two failed nodes and so on.<\/li>\n
  2. VM\u2019s with inbound connections on ports 2888, 3888 and 2181. If IPtables is enabled, make sure you enable the specified ports because zookeeper communication happens through these ports.<\/li>\n<\/ol>\n

    Note: If you are using AWS or any other cloud provider, apart from server level inbound connections, make sure you enable the security groups or endpoints for the zookeeper ports.<\/p>\n

    Install and Configure Zookeeper<\/h3>\n

    You need to perform the following steps in all the three VM’s.<\/p>\n

      \n
    1. Update your server.<\/li>\n<\/ol>\n
      sudo yum -y update<\/code><\/pre>\n
        \n
      1. Install Java if is not installed.<\/li>\n<\/ol>\n
        sudo yum  -y install java-1.7.0-openjdk<\/code><\/pre>\n
          \n
        1. Download zookeeper. b If you wish to choose another version, you can get the download links from here.<\/li>\n<\/ol>\n
          wget http:\/\/mirror.fibergrid.in\/apache\/zookeeper\/zookeeper-3.5.2-alpha\/zookeeper-3.5.2-alpha.tar.gz<\/code><\/pre>\n
            \n
          1. Untar the application to \/opt folder<\/li>\n<\/ol>\n
            sudo tar -xf zookeeper-3.5.2-alpha.tar.gz -C \/opt\/<\/code><\/pre>\n
              \n
            1. Rename the zookeeper app directory<\/li>\n<\/ol>\n
              cd \/opt sudo mv zookeeper-* zookeeper<\/code><\/pre>\n
                \n
              1. Create a zoo.cfg file in \/opt\/zookeeper\/conf directory with the configurations shown below.<\/li>\n<\/ol>\n
                tickTime=2000\ndataDir=\/var\/lib\/zookeeper\nclientPort=2181\ninitLimit=5\nsyncLimit=2\nserver.1=<ZooKeeper_IP\/hostname>:2888:3888\nserver.2=<ZooKeeper_iP\/hostname>:2888:3888\nserver.3=<ZooKeeper_iP\/hostname>:2888:3888<\/code><\/pre>\n
                In the above code, server 1, 2 and 3 represent our three zookeeper servers. You need to replace the Zookeeper_IP with relevant IP or resolvable hostnames.<\/p>\n
                  \n
                1. Create a zookeeper directory in the lib folder. Thar will be zookeepers data directory as mentioned in the zoo.cfg file.<\/li>\n<\/ol>\n
                  sudo mkdir \/var\/lib\/zookeeper<\/code><\/pre>\n
                    \n
                  1. Create a file name myid in \/var\/lib\/zookeeper\/ directory .<\/li>\n<\/ol>\n
                    sudo touch \/var\/lib\/zookeeper\/myid<\/code><\/pre>\n
                      \n
                    1. Each zookeeper server should have a unique number in the myid file. For example, server 1 will have value 1, server 2 will have value 2 and so on.<\/li>\n<\/ol>\n
                      server 1<\/strong><\/p>\n
                      sudo sh -c \"echo '1' > \/var\/lib\/zookeeper\/myid\"<\/code><\/pre>\n
                      server 2<\/strong><\/p>\n
                      sudo sh -c \"echo '2' > \/var\/lib\/zookeeper\/myid\"<\/code><\/pre>\n
                      server 1<\/strong><\/p>\n
                      sudo sh -c \"echo '3' > \/var\/lib\/zookeeper\/myid\"<\/code><\/pre>\n
                      Configuring Zookeeper as a Service<\/h3>\n
                      Zookeeper can be started and stopped using the scripts. But it is good to run it as a service to manage it in an elegant way.<\/p>\n
                        \n
                      1. Open zkServer.zh file for editing.<\/li>\n<\/ol>\n
                        sudo vi \/opt\/zookeeper\/bin\/zkServer.sh<\/code><\/pre>\n
                          \n
                        1. Add the following below the shebang \u201c#!\/usr\/bin\/env bash\u201d to add zookeeper to the system start up.<\/li>\n<\/ol>\n
                          # description: Zookeeper Start Stop Restart\n# processname: zookeeper\n# chkconfig: 244 30 80<\/code><\/pre>\n
                            \n
                          1. Find a line which says \u201c# use POSTIX interface, symlink is followed automatically\u201d. Replace the existing variables after that line with the following.<\/li>\n<\/ol>\n
                            ZOOSH=`readlink $0`\nZOOBIN=`dirname $ZOOSH`\nZOOBINDIR=`cd $ZOOBIN; pwd`\nZOO_LOG_DIR=`echo $ZOOBIN`<\/code><\/pre>\n
                              \n
                            1. Now, create a symlink for the zookeeper service.<\/li>\n<\/ol>\n
                              sudo ln -s \/opt\/zookeeper\/bin\/zkServer.sh \/etc\/init.d\/zookeeper<\/code><\/pre>\n
                              5. Add zookeeper to the boot menu.<\/p>\n
                              sudo chkconfig zookeeper on<\/code><\/pre>\n
                                \n
                              1. Now, Restart all the servers.<\/li>\n<\/ol>\n
                                sudo  init 6<\/code><\/pre>\n
                                  \n
                                1. Once restarted, you can manage zookeeper servers using the following commands.<\/li>\n<\/ol>\n
                                  sudo service zookeeper status\nsudo service zookeeper stop\nsudo service zookeeper start\nsudo service zookeeper restart<\/code><\/pre>\n
                                    \n
                                  1. When you check the status, it should produce an output like the following.<\/li>\n<\/ol>\n
                                    \/bin\/java\nZooKeeper JMX enabled by default\nUsing config: \/opt\/zookeeper\/bin\/..\/conf\/zoo.cfg\nClient port found: 2181. Client address: localhost.\nMode: leader<\/code><\/pre>\n
                                    out of three servers, one will be in leader mode and other two will be in follower mode.<\/p>\n
                                    \n
                                    Ngu\u1ed3n:<\/strong> How To Setup a Zookeeper Cluster – Beginners Guide \u2014 DevOpsCube<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
                                    Source: https:\/\/devopscube.com\/how-to-setup-a-zookeeper-cluster\/<\/p>\n","protected":false},"author":1,"featured_media":730,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-729","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-devops"],"_links":{"self":[{"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=\/wp\/v2\/posts\/729","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=729"}],"version-history":[{"count":0,"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=\/wp\/v2\/posts\/729\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=\/wp\/v2\/media\/730"}],"wp:attachment":[{"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=729"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=729"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.ngocha.biz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=729"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}